The present invention relates to a wiper for machine tools which is operated on sliding surfaces of machine tools and industrial machines to scrape chips, cutting lubricants, and the like which are present on the sliding surfaces, for the purpose of preventing these chips and cutting lubricants from entering the sliding surfaces.
Conventionally, a wiper used to remove chips and cutting lubricants from a machine tool includes a lip portion having a sliding portion which is typically made of a rubber material. The reason a rubber material is adopted is that the elasticity thereof is utilized to improve the conforming and scraping capabilities of the wiper in all directions.
Recently, a machine system which does not use a cutting lubricant (dry cutting) in order to avoid environmental issues, a high-speed type machine tool, and the like have been developed. Especially for these machines, a sliding portion of a wiper suffers from significant abrasion due to the high coefficient of friction of rubber and therefore, the closeness of the sliding portion of the wiper to the sliding surface cannot long for a long time.
To address the above problem, a wiper including a sliding portion made of thin spring steel has been proposed. However, when such a wiper is transported in a package made of corrugated cardboard, the wiper is often deformed due to its thinness, causing inconvenience of handling. Further, when such a wiper is used, scattered chips strike and bend the spring steel, resulting in a reduction in the closeness of the wiper. Furthermore, since spring steel is a metallic material, sliding surfaces may be damaged, or the spring steel may be corroded.
A wiper for machine tools according to ther present invention includes an attachment portion to be attached to a machine tool, wherein the machine tool is moved relative to a sliding surface, and a wiper body made of an elastic material integrated with the attachment portion. A lip portion of the wiper body can be slid on the sliding surface, and a fabric material is provided on at least a sliding surface side of the lip portion of the wiper body.
In one embodiment, the fabric material is made of at least one material selected from the group consisting of aromatic polyamide, aliphatic polyamide, and polyester.
In one embodiment, the lip portion of the wiper body is covered with the fabric material.
In one embodiment, the fabric material is made of weave fabric or knit fabric, and a thickness of the fabric material is 0.5 mm or more.
In one embodiment, a fineness of a thread included in the fabric material is 100 deniers or more.
In one embodiment, a coefficient of friction of a thread included in the fabric material is in the range of 0.1 to 0.3.
Since a fabric material is provided on at least a sliding side of a lip portion of a wiper, the coefficient of friction of the lip portion with a sliding surface is reduced and abrasion loss is reduced. Therefore, closeness can be maintained for a long time. Further, the low coefficient of friction allows the wiper to be slid at a high rate. Further, since a sliding portion of the lip portion includes a fabric material, a sliding surface does not suffer from scratches which would be otherwise observed when the sliding portion is made of a metallic material. A defective product due to warpage of a wiper caused by collision or impact with chips, or the like, can be avoided.
When a fabric material (fabric layer) to be abraded by fast sliding operations has a small thickness, a wiper body made of an elastic material, such as rubber, underlying the fabric material is exposed. In this case, friction resistance is increased and abrasion is rapidly increased.
To avoid this, the thickness of a fabric material (original fabric) is set to be 0.5 mm or more (particularly 1 mm or more), or the fineness of a thread included in the fabric material is set to be 100 deniers or more (particularly, the fineness of wefts extending in a direction perpendicular to a sliding direction is set to 400 deniers or more). Therefore, the life of the wiper can be lengthened in fast sliding operations.
According to the present invention, at least a lip portion of a wiper body is covered with a fabric material, whereby the friction resistance of the lip portion is small and therefore a fast sliding operation can be performed and the amount of leaked chips is small over long-term use. Further, since a sliding portion of the lip portion includes a fabric material, a sliding surface does not suffer from scratches which would be otherwise observed when the sliding portion is made of a metallic material. A defective product due to warpage of a wiper caused by collision or impact with chips, or the like, can be avoided.
Therefore, the wiper of the present invention can be used for machine tools which are moved at a high speed. Further, since scraping can be satisfactorily performed in an operation without cutting oil, the wiper of the present invention is applicable to particular operations, such as aluminum cutting.